1. Field of the Invention
The present invention relates to a process for producing a hydrogen absorbing alloy powder, and particularly to a process for producing a hydrogen absorbing alloy powder which is an aggregate of alloy particles each comprising a metal matrix and added-components, by conducting one of mechanical alloying and mechanical grinding, using an aggregate of metal matrix particles and an aggregate of added-component particles. The present invention also relates to a hydrogen absorbing alloy powder and to a hydrogen-storing tank including such hydrogen absorbing alloy powder therein.
2. Description of the Related Art
In this type of the producing process, a method is conventionally employed, in which metal matrix particles and added-component particles having the same particle size (usually 1 μm or more) or the substantially same particle size are used, and relatively hard added-component particles are sufficiently finely-milled, and then made to penetrate and dispersed uniformly into the metal matrix particles.
However, the above conventional process suffers from a problem that milling must be carried out, for example, for several ten hours in order that the added-component particles may be finely milled and made to penetrate and dispersed uniformly, resulting in an increased manufacture cost for the hydrogen absorbing alloy powder.
Various hydrogen absorbing alloy powders are conventionally known. However, the conventionally known hydrogen absorbing alloy powders are accompanied by a problem that a hydrogen storage capacity and a rate of hydrogen absorption/desorption are insufficient for the purpose of using such hydrogen absorbing alloy powder as being mounted in a fuel cell electric vehicle.